As with every other acid, however, it still produces emissions when it comes in to contact with a carbon-alkaline, sulfite-containing developer.

Almost all paper developers contain a large amount of sodium sulfite to prevent oxidation; if you want to completely prevent the emissions caused when this comes into contact with a stop bath, you can use a water bath in place of a stop bath. However, it should be noted that without the abrupt change in pH-value from the acidic stop bath, the developing process will continue, albeit much more slowly.

600 g citric acid to make your own stop bath concentrate. Dilution the concentrate at a ratio of 1+30 to 1+40 to make the working solution.